QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rudolph, N. Articles by Betheil, J. J. Search for Related Content PubMed PubMed Citation Articles by Rudolph, N. Articles by Betheil, J. J.

Protein Synthesis in Liver and Brain Microsomes Isolated from Rats Fed a High Phenylalanine Diet¹

Department of Pediatrics and Department of Biochemistry, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461

The effect of feeding a diet of high phenylalanine content on in vitro protein synthesizing capacity of liver and brain microsomes was studied. Weanling rats were fed a high phenylalanine diet for periods up to 20 days, and pair-fed control animals were fed a diet in which the phenylalanine was replaced by an equivalent amount of casein. It was found that the microsomes isolated from the livers of animals on the high phenylalanine diet showed an increased capacity to incorporate L-¹⁴C-leucine and L-¹⁴C-phenylalanine. Brain microsomes from animals on the high phenylalanine diet showed no such increase in protein synthesizing capacity compared with that of the pair-fed control animals. There were no significant differences in the pool sizes of leucine or phenylalanine in the microsomes isolated from the livers of rats maintained on the different dietary regimens. The increased protein synthesizing capacity observed in the in vitro system was found to be dependent on the microsomal fraction and not due to changes in the activity of the supernatant enzymes.

² Present address: Department of Pediatrics, Maimonides Medical Center, Brooklyn, New York 11219.

Manuscript received 31 July 1969.